[python3-ldap] Feature requests: clearer errors

[Joseph L. Casale]

> I think re-raising as a subclass of LDAPException is better, because you can
> catch every problem with a single exception handler. This is also how Requests
> and urllib do it. It's also important that all possible exceptions are properly documented.

Just my opinion but I disagree with that. You can't know my use case and if you trap
an exception my scenario requires that yours doesn't, what am I to do?

If you don't want or care about the type, broaden your own try/catch, but don't impact
the usability of the library by such an approach.

jlc